Ceiling panels such as acoustical ceiling panels are generally suspended on support members. This invention deals with the type of ceiling panels that esthetically conceal the support members when viewed from below.
Many ceiling panels that conceal the support members are known from the prior art; however, they are liable to be dislodged from the support members and to cause damage when falling from the ceiling.
U.S. Pat. No. 6,108,994 discloses a ceiling panel having first and second opposing edges having different profiles with upper and lower lips. The first edge has a registration step and an access kerf at a first level below the registration step. The second edge has a registration kerf formed by the upper and lower lips at a second level above the first level. When the panel is assembled into the ceiling, the access kerf permits the registration kerf to engage, and form a hinge with, the support grid. The registration kerf permits the panel to be shifted and rotated to engage the registration step with the grid.
This prior art panel is formed by a complicated and therefore costly method for precisely forming the lips and kerfs of the first and second edges, particularly when the panel is made from difficult to cut mineral fiber. An additional drawback of this panel is that the assembly and removal procedures are time consuming, for example an exploratory upward lift is needed to identify the first edge. Also, the panel is liable to be dislodged from the support grid when a random force is applied thereto. Furthermore, two adjacent panels are assembled with significant play therebetween, to take into account the complicated assembly and removal procedures, and therefore side edges of a plurality of assembled panels invariably will not be coplanar, detracting from the esthetic appearance of the ceiling.
Other prior art concealed ceiling panels with other or similar drawbacks are U.S. Pat. No. 6,260,325 and U.S. Pat. No. 6,389,771.
The Casoline GRID panel disclosed in www.british-gypsum.com is provided with metal support sections attached to the upper planar surface of the panel, for engaging the upper face of the flange of a support member generally referred to as a “main runner”. The portions of the support sections that engage the main runner flange are substantially horizontally disposed. The disposition of the engaging portions, and consequently of the entire panel, is therefore dependent upon the disposition of the main runner. However, the main runner, which is generally made of thin-gauge sheet metal, e.g. of 0.4 mm thickness, and sensitive to applied loads, is supported by one or more hangars vertically extending from an overhead surface. Due to assembly inaccuracies, the hangars may not be positioned completely perpendicularly to the overhead surface and a panel supported by two adjacent main runners may be slightly oblique with respect to a neighboring panel as a result of the variance in perpendicularity of adjacent hangers that support a corresponding main runner from above. Thus the side edges of a plurality of assembled panels invariably will also not be coplanar, and adjacent side edges of laterally adjacent panels will not be mutually parallel, detracting from the esthetic appearance of the ceiling.
It is an object of the present invention to provide means for securing a ceiling panel in such a way that it will not be dislodged from adjacent concealed main runners during normal usage, yet is detachable from the main runners upon demand.
It is an additional object of the present invention to provide means for securing a ceiling panel such that the side edges of a plurality of assembled panels will be coplanar.
It is an additional object of the present invention to provide means for diminishing the influence of the hangar disposition on the disposition of the main runner flange and on the panel secured thereto.
Other objects and advantages of the invention will become apparent as the description proceeds.